Bafang error 45: Battery temperature too high
Bafang CAN systems (M400/M500/M600/M620, DP C18 CAN, 850C/860C CAN)WarningRide with caution
The BMS reports the pack is too hot and has cut or limited power. This typically appears after fast charging in the sun, or hard riding in hot weather. It clears once the cells cool.
Likely causes
- Charging or riding in high ambient temperatures
- Pack exposed to direct sunlight
- Sustained high current draw from the pack
- Faulty temperature sensor inside the pack
How to fix Bafang error 45
- Stop, move the bike into the shade and let the battery cool for 20-30 minutes
- Power cycle after cooling
- Charge indoors, out of direct sun
- If the code appears when the pack is clearly cool, have the BMS sensor checked
Go to a dealer if: Go to a shop if the code shows on a cool battery; the BMS temperature sensor is misreading.
Warranty: Battery warranty covers sensor faults; heat damage from leaving the bike in the sun does not count.
Typical cost: Usually free (cool down); BMS sensor repair EUR/USD 80-150.
Warranty: Battery warranty covers sensor faults; heat damage from leaving the bike in the sun does not count.
Typical cost: Usually free (cool down); BMS sensor repair EUR/USD 80-150.
Still stuck? Take a photo of the display and show it to a local e-bike workshop. Bring the bike's system name (e.g. Bosch Performance Line CX) and the exact code; that saves diagnostic time and money.
Frequently asked
Can I reset error 45?
Yes, it clears after cooling and a power cycle.
Can I keep riding?
After cooling yes; avoid full power in heat.
Warranty?
Only if the sensor is faulty.
Related Bafang codes
Not an official Bafang document. Compiled from workshop experience and public service information; details can differ per system version and bike brand.